Decorative laminates have been used as surfacing materials for many years, in both commercial and residential applications, where pleasing aesthetic effects in conjunction with desired functional behavior (such as superior wear, heat and stain resistance, cleanability and cost) are preferred. Typical applications have historically included furniture, kitchen countertops, table tops, store fixtures, bathroom vanity tops, cabinets, wall paneling, office partitions, and the like.
Laminates are useful as surfacing materials, including as decorative surfaces, in many situations due to their combination of desirable qualities (e.g., superior wear, heat and stain resistance, cleanability, and cost). Laminate surfaces are composed of discrete layers, such as layers of resin-impregnated kraft paper that are pressed to form the laminate. One conventional decorative laminate is made by stacking three sheets of treated kraft paper (e.g., three sheets of phenol-formaldehyde resin-impregnated kraft paper), dry decorative paper (e.g., a print sheet), and a sheet of treated overlay paper (e.g. melamine-formaldehyde resin-impregnated tissue paper or acrylic resin-impregnated tissue paper), one on top of another and then bonded together with heat and pressure.
A high-pressure laminate process (HPL) is an irreversible thermal process wherein resin-impregnated sheets of kraft paper undergo a simultaneous pressing and heating process at relatively high levels of heat and pressure, such as temperatures greater than or equal to 125° C. and at least 5 mega Pascals (MPa) of pressure, typically for a press cycle of 30-50 minutes. An HPL process contrasts with low pressure laminate processes (LPL) that is conducted at pressures of less than 5.0 MPa, typically between 2-3 MPa.